Plesiosaurs, a species of giant marine reptiles which lived in the oceans 75 million years ago, is now being theorized as birth-giving mothers like mammals and may have even nurtured their young.

As noted at Los Angeles Times on Thursday, August 11, 2011, a pregnant plesiosaur fossil and her unborn baby, which was discovered in 1987, has been studied closer by experts starting 2008.

The pregnant fossil, which was discovered by amateur paleontologists Marion and Charles Bonner while hiking in northwest Kansas, was noted to be the only known fossil of a plesiosaur mother.

Apparently, paleontologist F. Robin O’Keefe of Marshall University in Huntington, West Virginia, teamed up with Luis Chiappe, director of the Dinosaur Institute at the Natural History Museum in Los Angeles and conducted a closer study on the said plesiosaur fossil.

According to their report, which is also published at Science Journal that day, a lot similarities were found between the small bones beneath the abdominal part of the the larger fossil.

The research study noted that these similarities suggest that both fossils, which is now displayed at Dinosaur Hall of Natural History Museum, belong to a single species.

In addition, the appearance of both fossils was said to have indicated that a baby plesiosaur was growing inside the larger plesiosaur and was not its last meal.

“So we made the leap that plesiosaurs were very social, although we have no direct evidence,” Chiappe was quoted on the report, as plesiosaur‘s head and neck were never found.